I think a lot of new Magnepan owners owners find themselves surprised by that company’s speakers’ need for very high power at low impedances. I bought my first pair of Maggies---the original Tympani T-I---in 1973, and bi-amped it with an Audio Research D-75 and D-51 power amps. The original Maggie was an 8 ohm load, while all future models have been 4 ohm (dropping to 3 ohms at some frequencies).
My current Tympani T-IVa’s require massive amounts of power. When I have them set up (not currently possible), I bi-amp them using a PS Audio 200w/ch amp on the two bass panels, and a Music Reference RM-200 MK.2 on the tweeter/mid panels. Roger Modjeski designed the RM-200 to do two things: 1- produce 100 watts from a single pair of KT-88’s. And 2- To perform well into low impedance loudspeakers. The RM-200 (in original and MK.2 iterations) was Michael Fremer’s reference "affordable" tube amp for over a decade. The Magnepan ribbon tweeter, by the way, is a beauty, one of the best available.
In contrast, while the Eminent Technology LFT-8b shares roughly the same sensitivity as the Maggies (83-84dB), it’s 8 ohm impedance is much friendlier to tube amps. And if you bi-amp the LFT-8b (easy to do, as it has dual binding posts, one for the woofer, another for the t/m panel), the t/m panel presents an 11 ohm load, great for tube amps. Use any old amp on the woofer (I still have an Electron Kinetics Eagle 2A, a great low frequency reproducer), and either a Music Reference RM-9 Mk.2 (using 8 EL34 tubes) or RM-200 Mk.2 (4 KT88’s), both producing 125w into 8 ohms, plenty for the LFT-8b m/t panels.